Electromagnetism 2

Electromagnetism 2

By Bingxue Wang

Multiple Choice

Which of the following is the best definition of electromagnetism?

• the use of electricity to create magnets

• the use of magnets to generate electricity

• the interaction between electricity and magnetism

• the appearance in nature of objects that have both electric and magnetic fields

Multiple Choice

What kind of device is shown in the following diagram?

• motor

• electromagnet

• galvanometer

• Transformer

Multiple Choice

Which action will increase the deflection of the galvanometer pointer?

• The magnetic pole is reversed

• The number of turns of coils is increased

• The coil is made from insulated wire

• The magnet is slowly pushed into the coil

Multiple Choice

Which of the following is most likely an advantage of an electromagnet over a permanent magnet in an industrial application?

• An electromagnet is able to detect and measure a small electric current.

• An electromagnet is more durable and resistant to industrial processes.

• An electromagnet is able to transform electrical energy into mechanical energy.

• An electromagnet can easily be de-magnetized by cutting off the flow of electricity.

Multiple Choice

What is the name for this coiled wire that is wrapped around the iron core of the electromagnet?

• generator

• solenoid

• transformer

• motor

Multiple Choice

The following image shows a simple galvanometer consisting of a compass wrapped with wire. The ends of the wire are connected to the terminals of a battery, as shown:

What is one purpose of this instrument?

• to produce sounds

• to produce an electric field around the wire

• to amplify the electric current flowing through the wire

• to measure the strength of the electric current in the wire

• Changes electrical energy into mechanical energy.

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• Almost every time a device uses electricity to make something move, there is a motor involved.

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​Motor

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Label the name of the parts and describe it. Explain its function in a motor

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​Motor Parts

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Using a magnetic field to create an electric current in a wire.

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How increase the electric current? Read your handout and answer.​

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Electromagnetic Induction and Faraday's Law - YouTube

​Electric Induction

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Multiple Choice

Electromagnetic induction is taking place in this experiment. How much electricity is being produced?

• -10 Volts
• 10 Volts
• 100 Volts
• This question cannot be answered based on this image

Multiple Select

How could the experimenter increase the amount of electricity being induced by this experiment?

• Increase the number of coils
• Decrease the number of coils
• Flip the magnet around
• Nothing, the amount of electricity cannot be increased
• Move faster

Multiple Choice

The voltmeter is at 0 in this image. How would you manipulate the experiment to create electricity (measured in volts)?

• Flip the magnet around so the North pole is facing out
• Move the magnet back and forth
• Take the magnet out
• Add more coils around the paper cylinder

Multiple Choice

Daniel has a long piece of copper wire. He shapes the wire into a coil. What could Daniel do to cause electric current to flow through the wire?

• shake the wire very quickly

• submerge the wire into a pan of hot water

• move a bar magnet in and out of the wire coil

• connect the two free ends of the wire so that they form a closed path

use induction to increase or decrease the voltage of alternating current

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Transfomer

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Step up and step down Transfomer

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​Step-up: more turns of wire on the secondary side.

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Step-down: more turns of wire on the primary side.

Multiple Choice

What is the voltage produced across the secondary coil?

• 200

• 240

• 250

• 60

Multiple Choice

This picture is an example of a ___________

• Step- Up Transformer

• Step- Down Transformer

• DC Motor

• AC Generator

​Read the Voltage and current carefully. What is your conclusion?

Multiple Choice

How does a step-up transformer differ from a step-down transformer?

• A step-up transformer decreases both voltage and current; a step-down transformer increases both voltage and current.

• A step-up transformer increases both voltage and current; a step-down transformer decreases both voltage and current.

• A step-up transformer decreases voltage and increases current; a step-down transformer increases voltage and decreases current.

• A step-up transformer increases voltage and decreases current; a step-down transformer decreases voltage and increases current.

Use induction to change mechanical energy into electrical energy.

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Electric Generator

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Multiple Choice

What is the best word to describe a system in which a magnet moves in a coil of wire to produce electricity?

• electromagnet

• generator

• motor

• Transformer

Multiple Choice

Generators generate

• electricity

• mechanical energy

• heat

• chemical energy